1. Create a port when a debugger object is created for an isolate, use this

vm/debugger_api_impl.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_debugger_api.h"
 
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_state.h"
 #include "vm/debugger.h"
 #include "vm/isolate.h"
@@ skipping 82 matching lines @@
   if ((frame_index < 0) || (frame_index >= stack_trace->Length())) {
     return Api::NewError("argument 'frame_index' is out of range for %s",
                          CURRENT_FUNC);
   }
   *frame = reinterpret_cast<Dart_ActivationFrame>(
        stack_trace->ActivationFrameAt(frame_index));
   return Api::True(isolate);
 }
 
 
-DART_EXPORT void Dart_SetBreakpointHandler(
-                     Dart_BreakpointHandler bp_handler) {
+DART_EXPORT void Dart_SetBreakpointHandler(Dart_BreakpointHandler bp_handler) {
   BreakpointHandler* handler =
       reinterpret_cast<BreakpointHandler*>(bp_handler);
   Debugger::SetBreakpointHandler(handler);
 }
 
 
 static Dart_BreakpointResolvedHandler* bp_resolved_handler = NULL;
 static Dart_ExceptionThrownHandler* exc_thrown_handler = NULL;
 static Dart_IsolateEventHandler* isolate_event_handler = NULL;
 
@@ skipping 12 matching lines @@
   } else if (event->type == Debugger::kExceptionThrown) {
     if (exc_thrown_handler == NULL) {
       return;
     }
     Dart_Handle exception = Api::NewHandle(isolate, event->exception->raw());
     Dart_StackTrace trace =
         reinterpret_cast<Dart_StackTrace>(isolate->debugger()->StackTrace());
     (*exc_thrown_handler)(exception, trace);
   } else if (event->type == Debugger::kIsolateCreated) {
     if (isolate_event_handler != NULL) {
-      (*isolate_event_handler)(Api::CastIsolate(event->isolate), kCreated);
+      (*isolate_event_handler)(event->isolate_id, kCreated);
     }
   } else if (event->type == Debugger::kIsolateInterrupted) {
     if (isolate_event_handler != NULL) {
-      (*isolate_event_handler)(Api::CastIsolate(event->isolate), kInterrupted);
+      (*isolate_event_handler)(event->isolate_id, kInterrupted);
     }
   } else if (event->type == Debugger::kIsolateShutdown) {
     if (isolate_event_handler != NULL) {
-      (*isolate_event_handler)(Api::CastIsolate(event->isolate), kShutdown);
+      (*isolate_event_handler)(event->isolate_id, kShutdown);
     }
   } else {
     UNIMPLEMENTED();
   }
 }
 
 
 DART_EXPORT void Dart_SetBreakpointResolvedHandler(
                             Dart_BreakpointResolvedHandler handler) {
   bp_resolved_handler = handler;
@@ skipping 547 matching lines @@
   const Library& lib = Library::Handle(Library::GetLibrary(library_id));
   if (lib.IsNull()) {
     return Api::NewError("%s: %"Pd" is not a valid library id",
                          CURRENT_FUNC, library_id);
   }
   lib.set_debuggable(is_debuggable);
   return Api::True(isolate);
 }
 
 
+DART_EXPORT Dart_Isolate Dart_GetIsolate(Dart_IsolateId isolate_id) {
+  Isolate* isolate = PortMap::GetIsolate(isolate_id);
+  return Api::CastIsolate(isolate);
+}
+
 }  // namespace dart